Dear maintainer, I would like to tell you that I experienced precisely the same bug when installing Wheezy x64 using uefi on a machine where windows 7 was already installed.
My work around was to disable os-prober in grub by adding the line GRUB_DISABLE_OS_PROBER=true at the end of /etc/default/grub then I created a custom entry for windows 7 by adding menuentry "Windows 7" --class windows --class os { set root='(hd0,gpt3)' chainloader (${root})/EFI/Microsoft/Boot/bootmgfw.efi } to /etc/grub.d/40_custom and then updating grub by update-grub. Sorry I can't send system information right now because the machine is not mine and I haven't access to it at the moment. Hope this helps, Thanks for your work. -- Eddy F. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org